[OhSix]

The GMC 260/230 series motorhome was introduced in 1973 with production ending in 1978 as a result of the oil embargo.

Designed from the ground up to be a motorhome - no other OEM – before or since – has produced a purpose built RV from scratch like GM did. Literally every other RV ever to hit the road began life as a truck, van or body-less rolling chassis adopted to become a motorhome.
Distinguishing design elements include:
- 455 (or 413) big block power
- Front wheel drive, derived from the 1966 Olds Toronado & Cadillac El Dorado of later years
- Fiberglass nose and end caps
- Aluminum roof and body skins
- All aluminum body skeleton
- Pioneering use of spray/expanding foam insulation
- 6 wheel, fully independent suspension with rear swing arms & custom Firestone air springs.

By some standards, these coaches are tiny. Offered in 23 and 26 foot lengths, the flat floor and very low-to-the-ground chassis makes entry and one step up proposition, which is very different from other RV’s. Driver/passenger position is directly atop the drive train and front wheels. The huge windshields provide an unobstructed view of the road ahead. Passengers are often unnerved - at first - feeling a bit insecure until they acclimate to their surroundings. Depending on configuration, they can sleep up to 6, but are most comfortable for 2. When the oil embargo killed the worlds only purpose built motorhome, there were approximately 12K produced – about 8K still exist. The GMC registry shows there are owners all over the world. Apparently, they are popular in Europe because they can negotiate narrow road ways and are pretty unusual over there.

Until recently, the 40 year old GMC held the land speed record for a motorhome. A hot-rodded Fiat Doblo (a minivan conversion to an RV) beat her record. My coach (her name is TUG) is a 74, serial # 476. I’ve traced her history all the way back to her first purchase.

Much like the RL, there’s a dedicated group of GMC owners. Several of the more enthusiastic fans have started a cottage industry designing and selling components, bringing drive line mechanicals closer to modern standards.
There are specialist businesses dedicated to the GMC around the country. Most of them are very well known in the GMC owner community. Among the more famous is the GMC CoOp in Orlando. Jim Bounds has a reputation for full blown restorations, hyper custom modifications and generally advancing the 70’s era GMC into the current century. In the last year or so, he’s delivered $400,000 “resto-mods” and $200,000 freeways fliers, fully updated to crate motor “EMP proof” military grade diesels coupled to original (vastly improved) TH 425 transmissions.

While on business travel in Sarasota last week, I had time to visit family in Orlando, and sneak a visit with Jim last Saturday. He’s in the middle of expanding operations, moving a rather intimidating volume of gear 200 feet across a parking lot. After a quick call, he invited me over for a visit, literally waiting for me to get there – since Saturday isn’t a normal business day in his world.

What a treat! He showed me all around his old and new shops, even pointing out that he’s finally achieved a goal of installing a urinal in the “new” bathrooms in the new location. It’s a Duessy too. No picture though cuz, uh… it’s a pisser. What else does one need to know?

Here's a quick pictorial of what’s happening at the GMC Co-Op (he’s changed his domain name to “FirefightMarine” as his business grows into mobile fire suppression).

This is Jim behind the wheel of (one of) his coaches. This one is used for all kinds of things, including road trips - but she’s pretty much a yard dog – a little rough around the edges. She’s windowless, which - when you are accustomed to the bright interior of a window coach - is really odd. Definitely not to my liking…



Stepping inside the new shop, there are quite a few 40 year old road queens…



This ones a 23 footer. These are like driving a big van. Only more fun when equipped with a galley, head, sleep spaces and various goodies.



Another 23 footer.



For a fan, this is like being in a dream factory. Wish my paint was 1/2 as nice as any of these.



Continued...

 

[OhSix]

This beauty is virtually new in every respect. Pretty sure Jim said the owner is into this one for about $100K.



Lets go out to the yard of the old shop…
he shell you see in between the yellow and white 26 footers is an example of what happens in 40 year old vehicles when the owner spends $ on nice things but ignores the foundation. In this case, good maintenance and inspection would have prevented the fire that took her out. Somewhere in her history, somebody ran a wire or a fuel hose was left to rot and she burned pretty good. Jim’s talking about turning her remains into a 5th wheel. Pity that…



Several of the rigs here are slowly be cannibalized. When no more parts are around, fabrication takes over. And there are several enthusiasts doing just that.



This is Jim’s “flat bed” for moving stuff around the yard. LOL. An SOB (some other brand) that wasn’t very well cared for. This rig developed a roof leak, and in Florida, it doesn’t take long to kill metal. Especially the cheap ribbing used in SOB’s with names like “Fleetwood” and “Bounder”. Not exactly stout road machines, these things are known to rot from the inside.



Ever seen a motorhome in a wreck? They don’t do well. Although the metal in this Fleetwood has been sitting out a while, look at this crap! 1” wall struts butt welded to floor “joists” with no sealant, primer or coating in sight. I’m no fan of government regulations, but this B.S. shouldn’t be legal.



I hope someone saves this stock “Eleganza”. If the bones are good, she has potential.



Continued...

 

[OhSix]

Back in the shop, Jim’s upholstery guy brings in some wild rides for side jobs. This 57 Bel Air looks like it came from the factory this way.



Finally, here’s a good example of repowering a 40 year old vehicle. The Co-Op is fitting military GM diesels into front clips. Plumbed and ready to slide under a coach. This motor tops out at 2,200 RPM using mechanical fuel injection – hence – EMP proof. If a pulse bomb goes off in the vicinity, this motor will keep on going. It’s got a blower too!

 

[coolbob]

Very cool, thanks for sharing. I've always had a soft spot for weird/quirky vehicles.

 

[cccbock]

Very Cool.

My grandfather started his RV career with one of these, and graduated through a series of coaches until his last one, a custom built MCI coach with supercharged CAT diesel in the back. He installed the supercharger himself because he wanted to be able to pass the slowpokes in the Rocky Mountains!

But I always liked that first GMC coach best.

 

[chiph]

I saw a 26 footer running around town the other day. Looked to be in pretty decent shape, but nothing like the paint on those.

The stupid gas-operated refrigerators burn down more coaches than anything else. Even a mild restoration ought to include a residential fridge replacement.

Chip H.
(who, if he wins the lottery tonight, would probably buy a Prevost conversion)

 

[tmy3329]

Cool story. Thanx for sharing in this thread!

 

[OhSix]

I saw a 26 footer running around town the other day. Looked to be in pretty decent shape, but nothing like the paint on those.

The stupid gas-operated refrigerators burn down more coaches than anything else. Even a mild restoration ought to include a residential fridge replacement.

Chip H.
(who, if he wins the lottery tonight, would probably buy a Prevost conversion)

I dunno Chip, is it the stupid gas expansion fridge's fault or is it operator negligence? The Norcold tri-power in Tug has been running for 17 years now, and I have no idea how old it really is. DC powering that thing KILLS the house batteries, and running a generator full time is a pain (although I'm moving towards a pair of air cooled Hondas to replace my ancient Onan-The Barbarian) so I gotta say... I just LOVE running on propane. I run out of black water space WAY before running out of propane. Dry camping record: 2 weeks! Coulda never done that with a generator.

All you gotta do is keep the flue clear.

I'd join you in selecting a Prevost with lotto winnings

 

[Dnick]

Very Cool.... the first thoughts that entered my mind were OUCH - How much must it cost to replace one of those wind shields... or new bags for that custom Firestone air suspension.

Would be fun to drive one of those on a road trip however..... yes, very cool.

 

[chiph]

Regarding fires: Take a look at Colaw RV Salvage on Google Maps - about 1/3 of the units there have been burnt.

https://www.google.com/maps/place/C...2!3m1!1s0x87c88524da9317cb:0x648417611f8c0433

If I were going to keep the propane refrigerator, I'd install an extinguisher system back there.

Chip H.

 

[OhSix]

Very Cool.... the first thoughts that entered my mind were OUCH - How much must it cost to replace one of those wind shields... or new bags for that custom Firestone air suspension.

Would be fun to drive one of those on a road trip however..... yes, very cool.

Windshields are about $530 per side, and they aren't available from Safelight. From what I understand, you would want just any schmuk installing them either.

OEM air bags are long gone. NOS too. The "fix" is to upgrade to a 4 bag system which fixes a couple of functional design flaws and brings a whole new level of ride stability to boot. If I recall, the kit was a $1,400. And worth every dime. It was a direct bolt on, took me a couple of weekends to complete. Since this photo was taken, she's been treated to disc brakes back there.

 

[Carsmak]

Well, darn. I didn't win the PB tonight so no companion of TUG in my future.

When I saw the first picture, at first glance 'Six', I thought it was you, but I'm guessing your smile was a little bit larger. I'm certain you had a good time.

Since you seem to have a lot of knowledge on these, I wonder how many were used "destroyed" in the making of the movie "Stripes" and did any of them survive?

 

[OhSix]

Well, darn. I didn't win the PB tonight so no companion of TUG in my future.

When I saw the first picture, at first glance 'Six', I thought it was you, but I'm guessing your smile was a little bit larger. I'm certain you had a good time.

Since you seem to have a lot of knowledge on these, I wonder how many were used "destroyed" in the making of the movie "Stripes" and did any of them survive?

LOL! You nailed it Carsmak. He and I could be related, huh? Except I am much younger, thinner and more handsome than Jim. PFFFFT!

Jim probably thought I'd recently had BOTOX shots, cuz I couldn't wipe the stupid grin off my mug, even when discussing seriously sickening stuff like black water tank cleaning. He totally schooled me on the fuel supply circuit including vapor management, tank equalization, proper integration of mechanical & electric fuel pumps and correctly feeding the GIANT thermoquad carb.

The Urban Assault Vehicle is both a legend and a mystery in the GMC community. Apparently, there is little (read: no) information about the EM-50 build, who did it and where it is now. There's at least one cyber guy out there claiming the remains of the coach are in his possession but... who knows.

http://www.motornomadics.com/urban-assault-vehicle-from-stripes-gmc/

 

[OwnerCS]

That had to have been one of GM's best FWDs of all time. The chain was virtually indestructible.

 

[csimo]

Wow, this thread takes me back to my GMI days. One of the transmissions I had to learn was the THM425 (I also learned the THM400 series). The THM425 was interesting and ahead of its time. I remember seeing these motorhomes around at the time and I knew they used the THM425. I have some vague recollection of GM making a few of those motorhomes for a technology tour or something like that. I don't remember where they were assembled. The Eldorado and Toronado both used the same number of clutch plates, but the one for the motorhome replaced the spacers with additional clutch plates. We also made a light duty version of the transmission that was sold to some third party for a forklift or something (sorry just can't remember). The THM400 and THM425 used a lot of the same parts, but you had to reverse your logic to follow the power flow of the THM425.

That was a long time ago on a planet far far away. I had a passion to learn powertrain back then.

 

[5S Dude]

Man OhSix, Thanks for this window back in time...

Way back in 1973, my dad looked at this coach for a very long time and I can still remember the brochure laying across the kitchen table for weeks! http://www.gmcmotorhome.com/faq/73brochure.html

He bought our Winnebago Brave instead. But was very fond of the GMC engineering. I think our Brave was 13500.00 OTD and I remember him taking it back to the dealer to swap out the carb twice but it became our getaway machine and stayed in our family for 33 years. I sold it to buy the travel trailer to tow behind the Ridgeline.

Does anyone know the original purchase price of the GMC 230?

 

[OhSix]

OwnerCS & Joe,

Yes indeed, the TH425 is one tough tranny. Compact too. There's a spare sitting in storage ready for a rebuild when Tug needs it. I can pick the thing up solo (minus differential of course).


Note: that is NOT my spare.

GM lore asserts the 425 is "the strongest transmission ever produced" - given the TZE community is retrofitting 6.5L diesels, that legend may be true.

Check out what this crazy bastard did with the 425 - thats a 500 cu in block stuffed in a Fiero!



As mentioned, there are a number of enthusiasts bringing products to market especially to extend the life and drive-ability of these cool rigs. "Manny's tranny's" is one of them. Check out his page, he is perhaps the most prolific drivetrain developer around. One of the huge errors on GM's part when they stuffed the TH425 into a 12kLB chassis is they used the final drive ratio (4.07 I think) of large two door sedan in the TZE line. While the motor lumbers along @ freeway speed, getting there was sorta like drive a 36HP VW bus. Manny fixed that.

And having completed an front wheel bearing rebuild/A arm reinforcement project a while ago, Manny's adaptation of GM 1 ton knuckles is pure genius, giving owners longer component life, much easier service and complete access to the modern supply chain.

Even Alan Johnson had a short stint with the TZE, producing a 6 speed version of the TH425. He once had a Porsche dealer here in San Diego and downsized to a customizing shop. Way back when, I did a bunch of work on his show room cars and race team rigs. Dunno what happened to his business.

Joe, now you've got me curious. As a casual historian of the TZE, I don't recall a story of pre-pro's for a tour - but that would make total sense. Now I've got more research to do!

Here's a few links to current day GMC TZE vendors I've done business with:

http://www.thegmcmotorhomepeople.com/ (these guys purchased many GMC molds way back when - they are the "official" GMC parts supplier)
http://www.firefightmarine.com/gmccoop/ (This is Jim Bounds operation, the man mentioned in the OP)
http://appliedgmc.com/ (Jim Kanomata is a legend @ GMC meets)
http://idencorpgmc.com/ (sadly, Leigh has since passed away)

This site has links to the above - and many more.

http://gmcmhregistry.com/Vendors.html

 

[Car Compulsive]

Wow, this thread takes me back to my GMI days.

When did you graduate from GMI and what plant was your sponsor? (Sounds like Hydramatic.) My dad worked for NDH in Ohio and wanted me to attend GMI, but after a summer working in the plant, I wanted to go into pure science instead of engineering.

A guy I knew in HS entered GMI in about 73, name of Rob(?) Hare. I became involved with GMI / Kettering in the mid-80s when I worked for Digital and we sponsored a few GMI co-ops. I was on the corporate partners advisory council for a few years.

The son of a friend was sponsored by a certain US Govt agency and now works at the agency. I don't think his profs could revew much of his thesis as it was classified.

 

[csimo]

I gave a long detailed response, but some wack job decided to contact my alumni and asked questions about me. I didn't appreciate that and it caused concern for others. It was a wake up call for me. I won't post any more personal information.

Why someone would bother to contact my classmates and ask questions about me from 40 or more years ago is just plain sick.

i have not hid my identity. I've met hundreds of ROC members. But it's obvious that I need to keep my personal life and history private.

Whoever you are you're one sick bastard. No more info from me.

 

[OhSix]

I gave a long detailed response, but some wack job decided to contact my alumni and asked questions about me. I didn't appreciate that and it caused concern for others. It was a wake up call for me. I won't post any more personal information.

Why someone would bother to contact my classmates and ask questions about me from 40 or more years ago is just plain sick.

i have not hid my identity. I've met hundreds of ROC members. But it's obvious that I need to keep my personal life and history private.

Whoever you are you're one sick bastard. No more info from me.

Normal human beings enjoy learning a thing or two about others, especially in a special interest forum like this. Apparently, some humans see those things as (fill-in-the-blank).

Due to the actions of one mis-wired carbon unit lurking here, a small but valued part of the forum experience is diminished.

Sorry you were the victim here Joe. Personally, I enjoy reading about the path others have followed leading them to where they are now. I suppose the lesson is "keep it business", but I have the impression douchebags find excuses to act as they do regardless of post content.

<SIGH> such is life on the internet.